In recent years, electronic devices using electric power as a driving power, as typified by mobile devices such as mobile phones or notebook personal computers, are often used while being carried.
In addition, transportation means such as bicycles and automobiles which use electric power as a driving power have been developed in terms of its cleanness and safety in the aspect of environment.
It is difficult to supply power to such electronic devices and transportation means, which are used outdoors or while in motion, constantly from a commercial power supply distributed to each house, through wires. Therefore, portable electronic devices and transportation means incorporate batteries which are charged from a commercial power supply in advance and operate by being supplied with power from the batteries.
Thus, the operating time of electronic devices is limited by the amount of power stored in the battery. In order to use the electronic device continuously for a long time, a user needs to prepare a spare battery, or to find a commercial power supply from which the battery can be recharged near his destination.
Therefore, a contactless power feeding system has been proposed and a more efficient power feeding system in view of a problem with an obstacle and the like has been studied so that the battery can be fed with power even if there is no commercial power supply (see, e.g., Patent Document 1).